Acyl phenyl dithiophosphoric acids and their preparation



Patented Mar. 27, 1945 UNITED'JSTATE S PATENT OFFICE asizsss ,7, a a r wierrrrneurnmrnrornosrnomc ACIDS AND THEIR PREPARATION Elmer W. Cook, New York, N. Y., and William D. Thomas, Jr., Stamford, Conn., asai nors to .American Cyanamid Company, New York, N. Y.,

a corporation of Maine No Drawing.

Application December 10, 194 Serial No. 468,552

4 Claims. (or. 260-461) This invention relates to new chemical compounds and their preparation; more particularly to new compounds which may be'broadly designated as di-(acyl phenyl) -dithiophosphoric acids and salts thereof.

The di-(acyl phenyl) -dithiophosphoric acids oi the present invention may be represented by the general iormula RtUi-R:

in which R1 and Ba are alkyl, cycloalkyl or aryl radicals and R; and R4 are hydrogen or alkyl, cycloalkyl or aryl radicals. The salts of these compounds are also included within the scope oi our invention as set forth in the appended claims.

The di-(acyl phenyl) -dithiophosphoric acids and their salts are, in general, yellowish-brown viscous liquids or soft solids. Most 01 the compounds-oi this new class are water insoluble but easily soluble in most organic solvents and in lubricatinz oils. Thecompounds, particularlyservice. The carbonyl trolling the viscosity of lubricating and other oils. Because of their surface active properties some or the compounds of the group are useful in the flotation oi ores. Still others may be employed as insecticides and fungicides. Since these new compounds have good heat stability those which are liquid are valuable as plasticizers for synthetic rubber.

The di-(acyl phenyl) -dithiophosphoric acids,

of the present invention are prepared by reactim; an acylated phenol-with Post as described hereinafter., The acylated phenols which may be employed in our reaction to prepare new and useful compounds are those obtained by acylating phenol or an alkyl, cycloalkyl or aryl substituted phenol with alkyl, cycloalkyl or aryl acyl halides." Suitable acylatinz agents for this latter reaction include acyl halides such as acetyl chloride, butyryl chloride, caproyl chloride, lauroyl chloride, myristoyl' chloride, stearoyl chloride, naphthenoyl chloride, benaoyl chloride,

amyl benzoyl chloride, octyl benzoyl chloride, phenyl stearoyl chloride, and others. Particu larly useful as acylatins agents are those mixed acylhalides derived from mixed fatty acids obtained upon hydrolysis of animal, fish and vestable oils. These products contain varying proportions 01 diilerentlona chain fatty acid halides in admixture. The naphthenoyl chloride mentionedabove is composed of a mixture of various cycloaliphatic acyl halides such as are prepared from naphthenic acid, a product of the for and phosphorous content they may beadvantaaeously-added .to. ymid sear creases and other extreme pressure lubricants. Bein: water- -lnsoluble and polar'in character they are valuable in the Preparation of slushins oils. Most of the compound otthis new class have pour point depressinc properties andareuseiblinccnpetroleum industry.-

The alkyl, cycloalkyl and aryl suhfitituted phenols ,which may lie-employed byus afe easily obtained products of commerce such as, cresol,

isobutyl phenol, amyl phenol, tertiary amyl phenol, ethylhexyl phenol, n-octyl phenol, dodecyl .phenol, tetradecyl phenol, octadecyl phenol, cy-

clopentyl phenol, cyclohexyl phenol, P-hydroxybiphenyl and the Although the preparation of acylated phenols has been previously described some of the acylated phenols-employed by us are new compounds, and accordingly. preparation or some or the typical ones are given in the specific examples which follow. In general, however, the acyl phenols are prepared by treating phenol or an alkyl, cycloalkyl or aryl substituted phenol with an acyl halide of the type-disclosed above in the presence of anhydrous aluminum chloride followedby decomposition of the resulting aluminum complex with dilute hydrochloric acid and washing As will be seen from the above, R1 and R2 in the general formula are aliphatic, aromatic, or.

is expected to be in lubricating oils it is desir- 1 able that the compounds be easily soluble in hydrocarbon oils. For this reason R: and R4 in the general formula above are preferably straight or branched chain, primary, secondary or teritary alkyl radicals such as methylTethylr fl butyl, isobutyl, amyl, tertiary amyl, ethylhexyl, n-octyl, decyl, dodecyl, tetradecyl, octadecyl and the like or cycloalkyl radicals such as cyclopentyl, cyclohexyl, methylcyclohexyl, and other alkyl substituted cyclohexyl radicals, such as the ethyl, propyl, butyl, and amyl mono-, diand tri-substituted cyclohexyl radicals. Radicals of these types in the compounds promote oil solubility. R3 and R4 may also be hydrogen or aryl radicals particularly when R1 and R2 are alkyl or cycloalkyl radicals and when the compounds are intended to be used for purposes not requiring their solution in mineral oils.

Our new compounds may be prepared by mixing and heating approximately 4 mole of an acylated phenol or substituted acylated phenol as named above with one mol of P285 at temperatures between 80-l40 C. until most of the P285 has dissolved and the evolution of H28 has subsided. This usually requires 2-4 hours at these temperatures. If desired, an inert solvent such as toluene may be added to the reaction mixture, either before or after the reaction, to facilitate handling. The crude product may be decanted or filtered from unreactedPzSs and employed as such for certain purposes or it may acids may be prepared from the acids by simple neutralization of the above reaction product with a suitable salt-forming base or bydouble decomposition. A wide variety of salt-forming radicals including those of Ni, Al, Pb, Hg, Cd, Sn, Zn, Mg, Na, NH4, Ca, Sr, Ba and others may be introduced by neutralization of the acid with a corresponding oxide, hydroxide or carbonate or in some cases sulfide. Some of these salts are more easily prepared by double decomposition of the sodium salt of the di-(acyl phenylY-dithiophosphoric acid with a desired metal salt; as for example, zinc chloride or the like.

Preparation of our new compounds will now be described in greater detail by means of the following examples in which the preparation of representative (di-(acyl phenyD-dithiophosphoric acids and some of their salts are described. All parts are by weight unless otherwise stated. It will be understood that our invention is not limited to the preparation of these particular compounds since the examples are given primarilyfor purposes of illustration and our invention is to be construed as broadly as the appended claims permit.

Examrn: 1'

Preparation of di-(stearoyl phenyD-dithiophosphoric acid and its calcium salt A mixture of 230 parts by weight of stearoyl chloride and 71 parts by weight of dry phenol was stirred at'95 C. for one-half hour, cooled and diluted with 100 parts of octane. When 33.6 parts by weight of anhydrous aluminum chloride had beerfadfiedfihe"s ution was heatectwitii steam for two hours. After it had cooled, the product was stirred with warm dilute hydrochloric acid and the aqueous layer discarded. "The upper layer was washed with warm dilute hydrochloric acid again, but water three times, dilute sodium carbonate, and finallywith sodium sulfate solution. Before it was washed with sodium carbonate, the solution was mixed with butanol to decrease emulsification. The stearoylphenol was isolated by distilling the solvents from it in vacuo. The product, a viscous yellow colored liquid, solidified on standing and cooling. A mixture of 248 parts by weight of stearoylphenol and 42 parts by weight of P285, was stirred for three hours at a temperature of 95 C. and the resulting di-(stearoylphenyi)-dithiophosphoric acid decanted from the excess P235. The acid was diluted with 43 parts of ethanol, 43 parts oi absolute ethanol, and 1'72 parts of toluene and then 15 parts of calcium hydroxide was added slowly, followed by 3 parts of calcium hydroxide and 172 parts more of toluene. The solution of calcium di-(stearoylphenyD-dithiophosphate was treatedwith activated carbon, filtered and the solvents removed by, vacuum distillation. The product was a viscous reddish-brown liquid that became semisolid on standing. It was readily soluble in lubricating oil.

EXAMPLE 2 Preparation of di- (o-myristoyl-p-cyclohexyl-' l H: I v A:

A mixture of 114 parts by weight of myristoyl chloride and 81 parts by weight of p-cyclohexylphenol was stirred on a steam bath for one-half Preparation of di-(o-benzoyl p tion was stirred at 95 with activated carbon,

hour,'cooled and diluted with 50 parts of octane. When 21 parts of anhydrous aluminum chloride had been added, the mixture was stirred on a steam bath for two hours and after it had been cooled and diluted with 250 parts of toluene, the

aluminum complexes were decomposed with warm dilute hydrochloric acid. The upper layer was washed successivel with hot dilute hydrochloric acid, hot water twice, a warm solution of sodium carbonate with butanol to prevent emulsification, and finally with warm water. The toluene, octane, butanol, and water were removed by vacuum distillation leaving 165 parts by weight of o-myristoyl-p-cyclohexylphenol, a. yellowishbrown liquid. r

A mixture of 35 parts by weight of o-myristoyl p-cyclohexylphenol and 5.6 parts by weight of P255 was stirred at 95-110" C. for three hours and the resulting di-(o myristoyl-p-cyclohexylphenyl)-dithiophosphoric acid was decanted from a slight residue of unreacted Pass. The product was cooled, diluted with 26 parts of toluene, 6.5 parts of 95% ethanol, and 6.5 parts of absolute ethanol, and then reacted with 1.9 parts by weight of calcium hydroxide. Thesolutiomsjreated with activated carbon, filtered, and vacuum diso tilled to remove the solvents from the calcium di (o myristoyl p-cyclohexylphenyl) -dithiophosphate. The product, a brownish-yellow liquid was easily soluble in lubricating oil.

Exslsrts 3 octylphenyl) dithiophosphoric acid and its calcium salt With 100 parts by weight of p-octylphenol was mixed 69 parts of benzoyl chloride and the solu- C. fora halt hour. when the liquid had cooled. 50 parts of octane and 21.? Parts of anhydrous aluminum chloride were slowly introduced. The mixture was stirred for two hours on a steam bath and then, after the prod ucts wereat room temperature, 250 parts of toluene and an excess of warm dilute hydrochloric acid were added. The upper layer was w again with warm dilute hydrochloric acid and then twice with hot water, once withwarm aqueous sodium carbonate, and rlnally with warm water again. The solvents and water were removed by vacuum distillation, leaving 139 parts by weight or o-benzoyl-p-octylphenol, a viscous CsHiI.

yellowish-brown liquid.

A mixture of 38 parts by weight of o-benscyl-poctylphenol and 7.4 parts of Past was stirred at 95-110 C. for 2.5 hours, and then decanted from excess P185. The di-(o-bensoyl-poctylphenrlldithiophosphoric acid was diluted with 28 parts of toluene, '7 parts of absolute ethanol, and 7 parts of 95% ethanol and then reacted slowly with 2.4 parts by weight of calcium hydroxide. Finally 28 parts of toluene and 0.5 part of calcium hy-v droxide more were added, the mixture treated and filtered. The me- I ly with water. The solvents were evaporated un- Exmns-i Preparation of di-(o-naphthenoyl-p-amylphen- 1 -dithiophosphoric acid and its calcium salt ll 0 where R is a naphthenyl radical. i

. 64 parts p-tertiarylamylphenol was dissolved in 40 parts warm octane and parts naphthenoyl chloride added gradually with stirring. The solution was heated on the steam bath for 30 minutes, temperature and 1? stirring. Tli'eunixturesvas'gradually warmed up on the steam bath and heating continued for 2 hours. After cooling, the mixture was diluted with 150 cc. toluene and extracted with warm dilute hydrochloric acid three times, followed by warm dilute sodium carbonate solution and finalleaving o-naphthenoyl-pder reduced pressure fluorescent yellowishtertiarylamylphenol as a green liquid.

' 69 parts by weight or 'o-naphthenoyl-p-amylphenol was reacted with 13.2 parts by weight or P285 at -110" C. for three hours. The resulting di (o naphthenoyl-p-amylphenyl) -dithiophosphoric acid was decanted from the slight amount of Past residue and, after dilution with 52 parts of toluene, 13 parts of 95% ethanol, and

13 parts absolute ethanol, it was'reacted with 4.4 parts of calcium hydroxide. Finally, 0.8 part more of calcium hydroxidewas added with 52 arts of Solvesso and the mixture was warmed to 60 C. for a half hour. Activated carbon was stirred in, the liquid filtered, and the solvents removed by vacuum distillation, leaving the cium di-(o-naphthenoyl-p-amylphenyl) dithiophosphate. The product was yellowish-brown and was easily soluble in oil.

EXAllPl-l 5 Preparation h 01' 'di-(o-laurowl p ter'tianlamul- :glenvl) -dithiopnosphoric acid and its barium t HsC 0 on. CHsCHi- -Cnflfl HttCir -CHsCHg HI 1 Ha I o s s o r I 2 0 s-m-s o the 0m On ons- -cnHfl KssCu-C -CHICH: Ha HI 164 by weight or p-tertiaryamylphenol was warmed with 219parts lauroyl chloride on the steam bath for 30 minutes. Alter cooling. Q0 parts octane was added, iollowed by 45 parts anhydrous aluminum chlorlde. The mixture was stlrredand slowlywarmeduponthesteambath. Heaths was continued for 2 hours.

2 Mid,

toluene was added and alter cooling down was o-Lauroyl-p-tertiaryamylphenol remained as a b brownish-yellow liquid.

346 parts o-lauroyl-p-tertiaryamylphenol was stirred and warmed with 61 parts finely ground Pass-at 125-13559. tor 2.5 hours. At the end of this time practicallvall of the Pass had disap- 5 peared and the evolution of. H28 had practically ceased. The crude di-(lauroyl-p-tertiaryamylq phenyl) -dithiophosphoric acid was decanted from a small amount of unreacted Pass. It was a brownish-yellow liquid.

78 parts di-(o-lauroyl-p-tertiaryamylphenyl)- dithiophosphoric acid was dissolved in a mixture of 40 parts toluene and 20 parts 97.5% alcohol.

With stirring and cooling below 40 C. 10 parts finely ground barium oxide was added. As soon dithiophosphate was a yellowish-brown thick viscous liquid.

We claim:

1. Chemical compounds having the general formula 1 in which R1, R2, R3 and R4 are alkyl radicals, and the salts of such compounds.

2. Di-(o-lauroyl p tertiaryamylphenyl) -dithiophosphoric acid and the saltsof such compounds.

3. Di- (stearoylphenyl) -dithlophosphoric acid and the salts of suchcompounds.

4. Di-(o naphthenoyl=p=te1tiaryamylphenyl as llama}, which required about 10 um 5 dithiophosphoric acid and the salts of such comfi/barts toluene was added and the solution filtered from traces of inorganic barium salts. The solvent was removed by evaporation in vacuo. The barium di-(o-lauroyl p'- tertiaryainylphenyl).-

pounds.

ELMER W. COOK. WILLIAM D. THOMAS, JR. 

